Variation in wood properties of six natural acacia hybrid clones in northern Vietnam

Wood properties of six 8-year-old natural acacia hybrid clones between Acacia mangium and Acacia auriculiformis, planted in Bavi, Vietnam, were studied. The hybrid clones possessed obvious heterosis in growth and in some wood properties. The characteristics of growth, air-dry specific gravity, lengths of fibers and vessel elements, S₂ microfibril angle, green moisture content, and shrinkage were examined to clarify the variation among clones. From the results, the differences among the clones in growth and in some wood properties were significant. The pattern of distribution of specific gravity showed that there were low and high specific gravity zones in the stem. Specific gravity at stump height or at 3.0 m was useful for prediction of specific gravity in the whole tree stem. Moreover, clones with high specific gravity can be predicted at a young age. There was no significant correlation between diameter growth and specific gravity. Of the six clones studied, clone BV5 was selected as the best based on its growth ability and specific gravity. Part of this report was presented at the 57th Annual Meeting of the Japan Wood Research Society, Hiroshima, August 2007     

Genotype-environment interaction in wood basic density of Eucalyptus clones

Summary Wood basic density was determined in samples taken from eight-year-old trees of 26 Eucalyptus clones growing in tests at four sites in Brazil. Within-clone variation in basic density was low. The broad sense heritability of basic density was 0.96 when estimated from five clones growing on two sites and 0.64 when estimated from 26 clones on four sites. Analysis of variance showed that there were significant differences in basic density between clones and sites, and that the clone × site interaction was also significant. Regression analysis was used to examine the stability of clones over environments. There were marked differences in stability between clones (linear regression coefficients 0.03 to 1.93). Interactions were variable (coefficients of determination zero to 93%), and in most cases it was not possible to predict the basic density of wood produced at one site from its value at another site. However, interactions accounted for less than 4% of the total variance in basic density; rank correlations between sites were all significant, and it was possible to identify clones which produced wood of consistently high or low basic density on the four test sites. Received: 9 September 1998     

Growth,productivity and water use in three hybrid poplar clones

Three drought treatments (none, medium and severe) were applied to three container-grown, hybrid poplar clones (Beaupré, Trichobel and Ghoy) as a series of drying cycles over two years-in a greenhouse in 1994 and outside in 1995. Leaf area development, annual biomass production and annual water use were recorded. Clone Beaupré had greater rates of leaf area development (up to 11.8 x 10(-4) m(2) degrees C day(-1)) and subsequently greater dry matter production (up to 816 g tree(-1) year(-1)) and water use (up to 168 l tree(-1) year(-1)) than the other two clones. In all clones, rates of leaf area development, annual biomass production and water use were less under drought conditions than under well-watered conditions. On a proportional basis, the highest reduction in biomass by drought was in Trichobel (up to 74%), whereas, in absolute terms, the reduction was greatest in Beaupré (up to 500 g tree(-1)). However, under drought conditions, annual biomass production was greater in Clone Beaupré than in the other clones. The relationship between water use and biomass production was constant over both years, and was similar for Beaupré and Trichobel at 4.4 g l(-1), but was less for Ghoy at 3.5 g l(-1).     

Genotypic parameters of wood density and fiber traits in triploid hybrid clones of Populus tomentosa at five clonal trials

? Context

A clear understanding of the genetic control of wood properties is a prerequisite for breeding for higher wood quality in Populus tomentosa Carr. hybrid clones.

? Aims

The experiments aimed at unraveling genetic and environmental effects on wood properties among triploid hybrid clones of P. tomentosa.

? Methods

We used 5-year-old clonal trials established in Northern China to assess the heritability of wood density and fiber traits. Two hundred seventy trees from nine clones were sampled in five sites.

? Results

Site had a very significant effect on all recorded traits. Despite this large site effect, a tight genetic control was detected and clonal repeatability varied between 0.53 and 0.95. Significant genotype?×?environment interactions were detected for most of the traits. Moderate to tight correlation were evidenced among traits but they were not consistent with that in several cases that were site-dependent.

? Conclusions

Our results revealed a tight genetic control over several wood properties and therefore breeding programs might be able to improve wood density, fiber length, and coarseness in these hybrids.     

柳树杂种木材基本密度的遗传变异

利用柳属和钻天柳属种间、属间杂交１５个杂种３９个杂交组合１５１个无性系材料，对木材基本密度的遗传变异情况进行了研究。结果表明，杂种间和无性系间，在木材基本密度上存在极显著（α＝０．０１）差异，其中属间杂种（旱柳×钻天柳）×旱柳平均木材基本密度达到０．４８８，显著（α＝０．０５）超过各杂种平均值；柳树杂种及无性系木材基本密度是受强遗传控制的，被研究群体的广义遗传力达到０．９２￣０．９８，遗传变异系数     

Growth variations and stability analyses of seven poplar clones at three sites in northeast China

Growth characteristics have complex inheritance patterns and genotype(G) by environment(E) interaction make predicting tree response to environmental changes difficult.In this study,the growth of seven poplar clones at three different sites was taken as the research focus,and heights and basal diameters were investigated in the second growing season.An ANOVA showed that all main effects,site,clone number and their interactions were highly significant in the overall F-tests.The coefficients of variation and repeatability of different traits ranged from 15.5 to 43.9%and from 0.549 to 0.912,respectively.AMMI(Additive Main Effects and Multiplicative Interaction) analysis results showed that genotype,environment and G × E interaction were significantly highly correlated.The stability analysis indicated that different clones showed different growth traits on different sites,which suggests that elite clones should be selected separately for different sites.Based on the growth traits,under a 10% selection rate,three clones were selected for different sites and the genetic gains of growth traits ranged from 4.7 to 11.2%.The three selected clones could be used to establish plantations in the future in different sites.     

乔木柳无性系木材基本朱内变异的研究

利用乔木柳12年生无性系对比试验林的材料，研究了13个柳树无性系木材基本密度株内径向和纵向的变异模式，并对密度选择的时期和取样位置进行了探讨。结果表明：（1）在1.3m高度，乔木柳无性系各年轮组木材戏向变异多数为“M”型曲线，即从木芯向外第、至第3年轮组（1－6a）的木材密度逐渐增加，第4年轮组（7－8a）略有下降，第5年轮组（9－10a）又有明显增加，至最外侧年轮（11－12a）木材密度则显著下降，根据各无性系的变异特点，分成3种类型，其中无性系221的变异较为独特，为典型的“N”型；（2）乔木柳无性系生长期密度变化的规律为：1－2年生时木材基本密度相对较低，3－4a以后密度相对稳定并接近无性系加权平均密度，3－4年生时木材基本密度与5－12年生时的测定值相关系数为0.789－0.985，均达到极显著相关水平（α＝0.01），5－12年生乔木柳无性系木材基本密度的变异为62.2％－97.0％与3－4年生时木材基本密度的值有关，3－4a作为5百木柳木材基本密度的选择年龄最为合适；（3）供试群体木材密度株内纵向变异模式大多也可用“M”型曲线加以描述，具典型的苴孔材绷向密度变异特征，根据各无性系的变异特点，分成4种变异类型；树干高1.3，3.6和7.2m处的木材基本密度与无性系平均密度的相关系数达到显著和极显著水平，可以在树干1.3m处取样以推测无性系平均值；（4）在供试群体中，有的无性系木材基本密度纵向和径向变异的幅度均很小，木材较为均一，如苏柳791，表明在乔木柳杂种后代中选择木材均一的柳树新品种是可能的。     

Behavior of wood basic density according to environmental variablesOA

The relationships between climate conditions and wood density in tropical forests are still poorly understood.To quantify spatial dependence of wood density in the state of Minas Gerais(MG,Brazil),map spatial distribution of density,and correlate density with climate variables,we extracted data from the Forest Inventory of Minas Gerais for 1988 trees scaled throughout the territory and measured wood density of discs removed from the trees.Environmental variables were extracted from the database ...     

Vertical variations in wood basic density for two softwood species

European Journal of Forest Research - Studies on wood basic density (BD) vertical variations become essential to predict more accurately the within-stem distributions of biomass and wood quality in...     

Genetic variation of wood tracheid traits and their relationships with growth and wood density in clones of Pinus tabuliformis

To improve wood quality for pulpwood industries, it is important to examine not only wood density but also its components, especially tracheid characteristics.We studied genetic variations in the following tracheid traits by earlywood(EW) and latewood(LW): tracheid length(TL),double wall thickness(WT), radial lumen diameter(R_D1), tangential lumen diameter(T_D1), radial central diameter(R_D2), and tangential central diameter(T_D2).We also studied the relationship with the following growth traits: diameter at breast height(DBH), height(H), crown breadth south-north axis(NSC), crown breadth east–west axis(EWC), ring width(RW), latewood percentage (LWP), and wood density(WD).All sample materials were collected from a 33-year old clonal seed orchard of Pinus tabuliformis Carr.Genetic variation among clones was moderate for all tracheid traits, 9.49–26.03%.Clones significantly affected WT, R_D1, R_D2, T_D1, T_D2, and the two ratios WT/R_D1 and TL/T_D2 in EW but had no effects in LW.Clones significantly affected TL in LW but had no effects in EW.H2/C was higher in LW(0.50) than in EW(0.20) for TL, while H2/Cwas higher in EW(0.27–0.46)for other tracheid traits and the two ratios(TL/T_D2 and WT/R_D1) than in EW(0.06–0.22).WD and TL were significantly positively correlated, but WT and TL were negatively correlated both at individual and clone levels;all tracheid diameters and the four ratio values(EW_WT/R_D1, LW_WT/R_D1, EW_TL/T_D2 and LW_TL/T_D2), were strongly positively correlated with DBH, H,NSC, WEC and RW, and strongly negatively correlated with WD both at individual and clone levels.The most important variables for predicting WD were LW_TL,EW_WT and R_D1 in both EW and LW(r~2= 0.22).Selecting the top 10% of the clones by DBH would improve DBH growth by 12.19%(wood density was reduced by 0.14%) and produced similar responses between EW and LW for all tracheid traits: a reduction of0.94 and 3.69% in tracheid length and increases in tracheid diameters(from 0.36 to 5.24%) and double wall thickness(0.07 and 0.87%).The two ratios WT/R_D1 and TL/T_D2 across tissues(EW and LW) declined 0.59 and 4.56%,respectively.The decreased tracheid length and the ratio between tracheid length and diameter is disadvantageous for pulp production.The unfavorable relationship of tracheid traits with wood density indicate that multiple trait selection using optimal economic weights and optimal breeding strategies are recommended for the current longterm breeding program for P.tabuliformis.     

Axial variations in anatomical properties and basic density of Eucalypt urograndis hybrid (Eucalyptus grandis 3 E. urophylla) clones

We studied two clones of Eucalypt urograndis hybrid (Eucalyptus grandis 9 E. urophylla), GR283 and GR330, grown in Tumkur district of Karnataka (India), and felled 5–6 years old three trees of each clo...     

Survival,growth, wood basic density and wood biomass of seven-year-old Casuarina species/provenances grown at Kongowe,Kibaha, Tanzania

A performance comparison of seven-year-old individuals of 13 Casuarina species/provenances in terms of survival, growth (diameter, height and volume), wood basic density and wood biomass was undertaken at Kongowe, Kibaha, Tanzania. The trial was laid out using a randomised complete block design with four replications. The results showed significant differences (P < 0.0001) in all parameters. Casuarina equisetifolia from Montazah National Park, Egypt, had the lowest untransformed survival (48.8%), whereas C. equisetifolia from Wagait Tower (North Timor), Indonesia, had the highest survival (87.5%). Casuarina equisetifolia from Montazah National Park, Egypt, had the lowest mean diameter (8.6 cm) while the C. junghuhniana provenance from Timor, Indonesia (seedlot no. 19489) had the highest diameter (14.8 cm). Casuarina equisetifolia from Montazah National Park, Egypt, had the lowest mean height (16.2 m), volume (22.1 m³ ha^?1) and biomass production (23.5 t ha^?1), whereas C. equisetifolia from Hadsamira Songkhla, Thailand, had the highest mean height (24.3 m), volume (66.4 m³ ha^?1) and biomass production (72.9 t ha^?1). In terms of wood basic density, the C. junghuhniana provenance from Timor, Indonesia (seedlot no. 19489) had the lowest (617 kg m^?3), whereas C. equisetifolia from Wagait Tower (North Timor), Indonesia, had the highest (731 kg m^?3). Ordinal ranking for the best-performing species/provenances revealed that the best two provenances were C. equisetifolia from Hadsamira Sonkhla, Thailand, and C. junghuhniana from Timor, Indonesia (seedlot no. 19491). The two poorest-performing provenances were C. equisetifolia from Montazah National Park, Egypt, and C. equisetifolia from Cotonou, Benin. The outstanding species/provenances are recommended for pilot planting at Kibaha and similar sites.     

Effect of growing site on the fundamental wood properties of natural hybrid clones of <Emphasis Type="Italic">Acacia</Emphasis> in Vietnam

We investigated clonal and site variations in wood fiber length, microfibril angle, and specific gravity of seven natural hybrid clones of Acacia (Acacia mangium × Acacia auriculiformis) grown in northern and southern Vietnam. Fiber length did not differ between clones or between sites. The microfibril angle of the S₂ layer did not significantly differ between clones but significantly differed between sites. Clone and site significantly affected specific gravity. The significant effects of genetic × environmental interactions on wood properties indicated the difference in the response of clones to different growing conditions. The trends of changes in fiber length, microfibril angle, and specific gravity from the vicinity of the pith to near the bark were similar for all clones at each site; however, variations in fiber length, microfibril angle, and specific gravity were more visible in northern Vietnam than in southern Vietnam, with a significant effect of genetic factors. This difference may be attributable to winter, which is experienced in northern Vietnam but not in southern Vietnam. For clone selection for plantation in the northern region, combining growth rate with wood properties was recommended. On the other hand, for plantation in the southern region, clone selection depends mainly on the growth rate, taking into consideration the specific gravity.     

A model for spatial wood density gradients in Norway spruce stems and stochastic between-stem dissimilarities for basic and dry density

Density is a fundamental softwood quality trait. The aim of this paper is to identify a spatial model for wood density variation in spruce stems, with the main focus on basic density. Six thousand 20-mm-wide cubes systematically sampled from 85 trees in western Norway were analysed. The overall radial density pattern was the J shape with local maximum in the pith and increasing density outwards from a minimum at some distance from the pith. The minimum appeared closer to the pith further up in the tree. The stochastic nature of the six tree-wise parameters defining density gradients from pith to surface and from base to top was analysed and described. The results provide information needed to simulate density variation inside stems and between stems in a population. Considering the fundamental influence of density on a range of wood traits, such simulation should be of great significance for scientific and industrial analyses.     

杨树新无性系木材性质的变异研究

The wood basic density, cellulose content and fiber form were investigated for all sample trees at breast height (1.3m) in seven poplar clones, and at 0 (butt), 5.6, 9.6, 13.6, 17.6, 19.6 and 21.6 m for clone Nanlin-95 and Nanlin-895, respectively,for providing information on variation patterns of wood density, fiber characteristics and holocellulose content within trees and among clones. The results showed that significant variations about wood density, cellulose content, fiber diameter and the ratio of fiber length to diameter existed among poplar clones examined. Variance analysis indicated that there were significant differences in wood basic density, fiber length, fiber diameter and cellulose content among the growth rings, which had an increasing tendency along the direction from pith to bark. The significant differences also existed in wood basic density, fiber length and fiber diameter at different tree height. The mean wood basic density had a general increase trend with increasing height of trees and the lowest was found at the base, while fiber length and fiber diameter had a general decline pattern with increasing height of trees and the biggest value was observed at the height of 5.6 m. Regression analysis indicated that the relationship between examined wood properties and growth ring number (cambial age), and the relationship between examined wood properties and tree height can be described by polynomial functions.     

Possibility of improvement in fundamental properties of wood of acacia hybrids by artificial hybridization

Growth, specific gravity, and wood fiber length of Acacia mangium, Acacia auriculiformis, artificial acacia hybrid clones, and combinations, which were planted in a trial forest in Bavi, Vietnam, in July 2001, were examined. The radial variations from pith to bark were investigated to clarify the effect of genetic factors on these traits. Superiority of hybrids over their parents ranged from 36.3% to 41.6% for diameter, from 20.0% to 25.3% for height, from 6.9% to 20.7% for specific gravity, and from 6.1% to 12.8% for wood fiber length. The hybrid possessed heterosis in diameter, height, specific gravity, and wood fiber length regardless of whether the female parent was A. mangium or A. auriculiformis. The profiles of wood fiber length and specific gravity in the radial direction were similar for all the trees investigated. Wood fiber length was initially 0.5–0.6 mm near the pith and then increased slowly, finally reaching 1.0–1.2 mm near the bark. The specific gravity of acacia increased from 0.49–0.58 near the pith to 0.63–0.74 near the bark. From a relative distance of 30% from the pith, the specific gravity increased slightly and seemed to be stable. The relations among tree diameter, specific gravity, and wood fiber length were fair and could be represented by positive linear regression formulas. Hybrids for which A. auriculiformis was the female parent and A. mangium was the male parent had a faster growth rate and longer wood fibers than the inverse hybrids. Part of this report was presented at the 6th Pacific Regional Wood Anatomy Conference, Kyoto, Japan, December 2005     

Near-infrared spectroscopy and wavelength selection for estimating basic density in Mimosa tenuiflora [Willd.] Poiret wood

The aim of the present work was to estimate the basic wood density of Mimosa tenuiflora by using near-infrared spectroscopy (NIRS). Fifty-eight wood samples representing sapwood, heartwood and pith were evaluated by gravimetric method and NIRS together with wavelength selection methods. A comparison was made among several multivariate calibration techniques and algorithms for preprocessing and variable selection of data, including full-spectrum partial least squares (PLS), interval PLS, backward interval PLS, synergy interval PLS, genetic algorithm-PLS and successive projections algorithm for interval partial least squares (iSPA–PLS). Finally, the results obtained using iSPA–PLS model for the root mean square error of calibration and prediction were 0.0383 and 0.0166 g/cm³, respectively. A t-test was performed to compare the results of the models with each other and with a reference method. NIRS and iSPA–PLS can be used to predict basic density of Mimosa tenuiflora [Willd.] Poiret wood samples rapidly. In addition, the basic density could also be predicted with only 17 wavelengths in the range from 2,090 to 2,208 nm that should allow for measurement of this parameter using handheld NIR spectrometer.     

Development of a method for sorting picea abies pulp wood with respect to basic density

The basic density of pulp wood can be used to convert green volume to dry weight, and as an indicator of the fibre quality. Because the methods for measuring basic density are cumbersome, a practical, on‐line method for sorting Norway spruce pulp wood with respect to basic density was developed. The relationship between mean annual ring width and basic density was used to sort the pulp wood. Brief visual inspection could separate piles of logs with different mean annual ring widths from each other with an acceptable precision. The resulting classes had significantly different mean basic densities (380, 400 and 434 kg m^?3). Means of other properties, such as juvenile wood content, heartwood content, and dry matter content, also differed among classes.     

Comparing the financial returns from acacia plantations with different plantation densities and rotation ages in Vietnam

In Vietnam, planted forests account for > 26% of total forest area, with approximately two-thirds of the plantation area managed by smallholders and 80% of plantation wood used for woodchip production. With increasing demand for timber for the construction and furniture industry, the Vietnam Government is seeking to encourage growers to increase the rotation age of plantations and produce higher quality timber so that it can meet its 2020 furniture export targets. Progress on this goal is however slow, with growers unsure about the financial case for increasing rotation age. Using a case study of the Ben Hai State Forestry Company (SFC), we compare financial returns from acacia plantations by the rotation ages of 5, 6 and 10 years. The 5 year rotation is for the sole purpose of producing woodchips whilst 6 and 10 year rotations produce both timber and woodchips. Results show that all three types of plantation produce positive returns but the return from 10 year rotation plantations (in terms of NPV and IRR) is much higher than those of others. By increasing the rotation age by 1 year (6 years total) and 5 years (10 years total) from the common practice of 5 years, the net present values from the modelled plantations would increase by about 1.57 times and 4.24 times respectively. The reasons why smallholder grower are not responding to these apparent higher present values and policies that would promote long rotation age plantations are discussed.     

红榉不同种源木材基本密度和干缩性比较

以湖南省6个红榉种源(天然种群)为研究对象,对其木材基本密度和径向全干干缩率等物理性质进行测定分析。结果表明:不同红榉种源间木材基本密度的差异达极显著,而种源内木材基本密度比较稳定,变异较小;不同种源间木材径向全干干缩率不存在显著差异,但种源内不同个体间的差异显著。红榉木材基本密度与径向全干干缩率相关性不显著。这2个性状基本上相互独立遗传,且两者与各地理气候因子相关性也不显著。